Water heaters are frequently used in supplying hot water to desired locations within a house, office building or other such structure. To regulate the temperature of water discharged by the water heater, a thermostatic mixing valve is typically connected to the hot water outlet of the water heater, allowing hot water discharged from the water heater to be mixed with cold water supplied to the structure in order to maintain a constant, pre-selected temperature. The tempered water discharged from the mixing valve can then be fed into the structure's hot water piping for use by the occupants. Such mixing valves are typically configured such that the temperature of the mixed water remains constant or nearly constant regardless of the temperature of hot and cold water supplied to the device, and regardless of the flow rate of hot and cold water supplied to the device.
With the construction of larger homes and an increased usage of hot water, the demand for water heaters having larger heating capacities has grown significantly. The demand for increased hot water capacity has also grown appreciably as a result of building codes and regulations (e.g. ASSE 1017) that limit the temperature of hot water that can be discharged from the water heater, affecting the ability of many water heaters to produce a sufficient volume of usable hot water. To overcome this limitation, many water heaters are configured to generate hot water at elevated temperatures greater than that desired or permitted by code, necessitating the use of a thermostatic mixing valve.